Actual Flying Rotax Installs

[Kai]

All,

Regarding the use of compressed air when replacing the oil in the tank: I stand corrected!

Kai

[Skippydiesel]

So with some work I have completed the install of my Rotax with the Sonex mount. With some tweaks to the water pump, elbow replacement and orientation, the Sonex mount works. I had run my engine for the first time today. It’s not yet synced and tuned but it started right up. Currently going to run it for an hour on non synthetic 10w-40 Castrol oil and a Fram filter to break in, tune, and collect all the crap, then I’ll be doing an oil change to the standard Aeroshell and Rotax filter. It’s a 912 with 84mm pistons and cylinders. I had tigged up an exhaust into duals, made a scoop that houses my radiator and oil cooler, and a few other things. I’m running a 64” 3 blade taper and nickel tipped Warp Drive. Right now this is what I have and it’s about ready to be flown. I have a DAR appointment this next weekend to get my airworthiness.

Very interesting; I have just checked out the information printed on my Aeroshell Oil Sport Plus 4 oil containers - no mention of viscosity at all. In fact very little information about the oil. Googled it & learnt a bit more - its a 10W/40 semi synthetic (blend mineral & synth). One particularly important feature is its compatibility with the gear box.

So wondering what is your rational for selecting a Castrol non synthetic 10W/40 and a Fram filter.

[Kai]

Flying Rotax with AeroVee hydraulic brakes:

Any of you Sonex flying R912ULS guys with the standard Aerovee brakes as supplied from Sonex in your plane?

Previously, with the Jab, my Aerovees would hold the plane amiably during static runup and mag tests. However, with the R912, this happy situation is a thing of the past: there is no way the brakes will hold much above 3000 rpm with that enormous paddle blade thing up front: not enough for the mag test.

Perhaps I should start looking for a master cylinder with increased capacity? If so, does anybody know where I could get one?

Thanks
Kai

[garyb]

I am running the Sonex standard brakes with the machined drums and also only hold up to 3000 RPM. I only really use them for Taxing and occasionally on short fields and find that they deteriorate quite rapidly when they get hot.

[Skippydiesel]

Try the ATEC catalogue page 11-12

https://www.atecaircraft.eu/storage/app ... omplet.pdf

[CaseyCooper]

Skippydiesel,

My Rotax in my Sonex isn’t new. It was sent to my friend Ronnie who is a iRmt and teaches Rotax maintenance courses, works the Rotax booth at Airventure, and produces aftermarket big bore kits and additional components for the Rotax series so I don’t question a word he says. I ran the oil and filter for. break in/cleaning period since the engine was torn down and reassembled with new components. In that period of time I just used it as a flush procedure which he does on every engine he breaks Into just to collect the crap, then throw in new Sport 4 and a Rotax filter.

Kai,

I’m using the Aeroconversion hydraulic brakes. I’m using toe brakes I designed I’m conjunction with 1/8” brake lines with 1/2” bore master cylinders. For all my mag checks I perform them at 3,500 rpm and they hold just fine. If you’re having issues you might try a new master and/or lines and fittings to help provide better braking force.

Zack,

Mark and I at Sonex were taking about that exact issue with the sump on the iS at Airventure and the banjo was the best option. Another that I had found that might work well is at Specialty Flightlines they produce a stainless banjo with about a 30 degree bend that would work wonderfully. They produce Teflon aircraft lines for whatever application. You just send them whatever measurement you have on line length, what fittings you’d like to use, and they make up the lines for you. The nice thing is they’ll last the lifetime of the engine anyway. As far as your cowling your on the right track with a bigger spinner. Because of the torque the Rotax produces, it should have a bigger cowl opening at its disposal. Mark and I had talked about. Blister that they may offer to Rotax users to integrate into their cowling for simpler installations. And as far as the radiators, he had mentioned installing them on the side next to the vents on the B cowls and the exhaust on the bottom. Because I have a vertically split cowl (and makes a molded in scoop complicated) and have found out just how well my plane cools, I’m redesigning my scoop so it’s more aerodynamic and restricts a position of the airflow to bring the temps up. I already have a mock up that recesses my radiators in flush and all in the one scoop. I’ll be making it out of carbon fiber to increase strength and durability. I’m also working on some other aerodynamic components, airframe related, that will hopefully help refine the plane further. I’m eager to see how your install comes along! Looks like you’re right on track with some great ideas.

[gcm52]

I installed Sonex hydraulic brakes on my Rotax 912 ULS powered Onex. They would not hold at 3000 rpm for the run-up which is supposed to be done at 4000 rpm. I looked for a replacement for the Sonex brakes. I liked Berringer brakes when I looked at them at Sun and Fun, but the cost would be north of $2000. I looked at O’Keefe brakes but they would not respond to phone calls or emails. I ended up installing Matco brakes for about $800 for the wheels and brakes and they work very very well. They basically will hold for a full power run-up and I could flat spot my tires if I put full braking power on during the roll out. ( I have dual toe brakes by the way) They offer a complete brake and wheel kit for the Onex which includes custom machined spacers that were very nicely done.

[Kai]

I mentioned the holding power of the Sonex hydraulic brakes installed in Rotax powered aircraft for Sonex Tech. They had little to suggest.

However, they made it abundantly clear that their brakes were intended for the direct drive engines they support, and not a geared powerhouse like the R912. That the brakes let go at around 3000 rpm did not surprise them at all. But they emphasized that any changes to their original design should ensure that these had no chance of putting a standard gear plane on its nose.

It seems I’m on my own here, so right now I’m toying with the idea of installing a second master cylinder as Sonex supplies- separate brake lines for each wheel caliper, operated by an identical hand lever.

Comments?
Kai

[Skippydiesel]

Kai - did you check out the parts catalogue I mentioned above ? - two different hand/master cylinder options.

[DCASonex]

Kia,
I have Great Plains (now O'Keef) brakes with custom differential toe pedal operators and came much too close to pulling my CAMit 3300 powered tail-dragger over on its nose when a stray gust of wind at end of runway of our hill top airport lifted the tail. MUCH TOO CLOSE! Now only do full power run-ups with tail tied to something immovable.

David A.